1. Field of the Invention
The present invention relates to a slide operation apparatus having a box in which a movable member is caused to move for parameter settings in response to an operation knob being operated.
2. Description of the Related Art
A slide operation apparatus such as a fader device mounted on a mixer or the like has conventionally been known (refer to Japanese Utility Model Registration Publication No. 3102188 and Japanese Patent Laid-open Publication No. 2002-008907). Generally, a slide operation apparatus includes a movable member caused to move in a box. For example, the movable member is adapted to be moved by manual operation of an operation knob, which is fixed to the movable member. A moving position of the movable member is detected, and based on the detected movable member position, parameter settings such as volume adjustment are carried out.
Generally, a movement guide formed by a rod circular in cross section is disposed in the box in the longitudinal direction, and the movable member is slidably engaged with the movement guide for movement in the longitudinal direction of the box by being guided by the movement guide.
In the aforesaid conventional slide operation apparatus, no substantial problem is caused as long as a force exerting only in the longitudinal direction of the movement guide is applied to the operation knob. In actual, however, a force is sometimes applied to the box in a direction perpendicular to the longitudinal direction of the movement guide (i.e., in the direction of pressing the operation knob downward or in the width direction of the box). In such a case, damages to the movement guide might be caused. To obviate this, the movement guide is made strong. Specifically, the movement guide is usually made thick and heavy, which poses a problem that the slide operation apparatus becomes large in weight and length.
Besides, the movement guide and the movable member are normally designed for very smooth sliding motion. Therefore, even when applying the operation knob with a large force exerting in the direction perpendicular to the longitudinal direction of the movement guide, a human operator is not aware of applying such force and can apply a much larger force to the operation knob. In addition, someone's hand or something can be in contact with the operation knob to inadvertently apply an excessive force thereto, posing a problem that the movement guide can be damaged.